I know that chocolate brown muscovies get lighter due to sunlight and they get back to their original color after the molt. But is it possible that the same feathers that got lighter can color back to their original colors or even darker? Cause that happend to my duck and I am confused now...

My muscovy got her color back after the molt, but she already turned lighter within a few months. But I don't know why but she is so dark right now. Way darker than she's ever been before. From far away the brown almost looks black. And it are the same feathers that were bleached in the sunlight. I've never seen this before. Since last 2 months(?) we have very gray cloudy days here, not much sunlight at all. It's rare to see the sun shine. I can't remember we ever had such bad months. So could that's be the reason?